Diplomacy is a popular turn based strategy game in which you battle to control Europe; to win you must be diplomatic and strategic. webDiplomacy lets you play Diplomacy online. Official game server: http://webdiplomacy.net/

WebDAV-Sync can synchronise a local directory with a WebDAV collection, which is useful when a lot of files are going to be accessed randomly. The tool is an Ant task and it also has a command-line interface. Try it with Pincette (pincette.biz).

OpenCHAT is a 100% HTTP and HTML based chat server written in Java. It has it´s own stand alone HTTP server integrated and does not need any Applet or special software on client side to run on, but only a frames enabled web browser.

Pebble is a lightweight, open source, Java EE blogging tool. It's small, fast and feature-rich with unrivalled ease of installation and use. Blog content is stored as XML files on disk and served up dynamically, so there's no need to install a database

JsMath is a means of including mathematical notation in web pages. It interprets TeX code within your document and uses JavaScript, CSS and unicode fonts to typeset the resulting formulas. It works across multiple browsers and platforms, without MathML

XPath Explorer (XPE) is a GUI application that lets you interactively experiment with XPath. Given an xpath and URL (to an HTML or XML document), it displays matching nodes and their values. This makes it easy to play with and debug your XPath expression

JODReports is a solution for generating dynamic documents and reports in Java based on the OpenDocument format (ODF). Templates can be easily composed with a word processor such as OpenOffice.org Writer. Data sources include POJOs and XML.

A Club member administration tool written in PHP using a MySQL database. Clubdata is highly configurable, supports different membership types, a lot of membership features, mass e-mails, Excel-export, PDF-export and sophisticated authentication. Club

Pushlets are a Java servlet-based mechanism where data is pushed directly from server-side Java objects to (Dynamic) HTML pages within a client-browser without using Java applets or plug-ins. See more detail on http://www.pushlets.com

Sarissa is a cross-browser ECMAScript lib that helps with browser incompatibilities in XMLHttpRequest/XML/XSLT/XPath along with some bonus utility methods. People call some of this Ajax nowdays, but the term was not available back in early 2003 ;-)

You could be doing a better job of website security... If only there was a simple way to implement SSL with signed keys? PHP-CA is an easy to use and easy to administer Certificate Authority that runs in PHP.

GraPHPite is a highly customizable utility written in OO PHP for creating charts or graphs (Bar, Area, Pie, etc).
Users are encouraged to switch to PEAR::Image_Graph which is based on GraPHPite source. GraPHPite is in maintenance only state.

tellmatic is a php and mysql based newsletter script to create, manage and send personalized newsletters or mass mails. uses wysiwyg and has a form editor. adresses and newsletter are stored in unlimited groups. handle bouncemails and failed adresses